The tongue is one of the main articulators used to shape the vocal tract to produce perceptually accurate speech. The strength of the tongue is routinely examined by speech-language pathologists when they attempt to diagnose and recommend treatments for patients with speech sound disorders. Typically measures of tongue strength are made subjectively. Thus, there are no standardized norms for tongue strength that clinicians can use to determine if the performance of an individual patient is normal or not. Moreover, little is known about the relation of maximal strength of the tongue and articulatory precision. Thus, studies are needed to address these issues in a systematic manner. A second measure that is of potential importance to speech production is that of fatigue. There have been no studies to date examining tongue fatigue. Yet, the time course of fatigue, its amount, and the time course of its recovery may be critical in maintaining accurate speech articulation. We have developed a portable, inexpensive, instrument for measuring tongue strength and fatigue, and have, in preliminary experiments, developed the procedures to be used with it. We propose to further study the tongue and its relation to speech by studying maximal tongue strength and tongue fatigue in a larger group of subjects for the purpose of developing normal standards and to examine the relation between these measures and accurate articulation as measured by speech sound production and intelligibility. The goal of the studies proposed here are to begin the study of strength and fatigue by looking at the anterior tongue. If these measures are informative, these studies will be used as a framework for examination of other aspects of tongue movement (e.g. lateral) as well as the strength and fatigue of other oral structures (e.g. lips).